Methods for recording specifications and other content of products, parts, etc. include, for example, color codes used for resistors (the example of replacing numerals of 0 to 9 with certain colors), bar codes, 2D codes, and other combination codes of dots, the Intacta code (registered trademark), etc.
Recording the above content using conventional bar codes etc. on the surface of a product, part, etc. is becoming difficult due to the increased diversity of parts (increase in amount of recorded information) and the increased miniaturization of parts (reduction of recording space).
Further, when recording content at products, parts, printed circuit boards, etc., it is considered necessary to be able to record the detailed manufacturing history from the viewpoint of identification or differentiation, inspection, searchability, and traceability. If based on this record, the history can be searched through. Recording such a detailed manufacturing history requires a relatively large space if using the conventional recording methods. With the existent products etc., there are many cases where display of such recorded content is sought despite the minimum required space not being present. It is extremely difficult to record such content with the conventional recording methods.
Further, with the conventional bar codes etc., writing the information required at each stage of the production of a product has been difficult due to the nature of things. Unrestricted recording in the code itself attached to a product was extremely difficult in terms of the system.
As prior art, there is the “Method of Recording of Identification Code for Printed Circuit Board, Method of Reading Identification Code, and Applied Apparatus” disclosed in Japanese Unexamined Patent Publication (Kokai) No. 3-229497. This prior art proposed the method of recording a large amount of identification information in the limited small space of a printed circuit board. FIG. 2 of that publication shows an identification code as a representative example. In this identification code, different sized rectangular patterns are combined and several simple colors are applied.
Further, the applicant previously made a proposal for utilization of color as a recording medium for information and for realization of a system of information conversion or information management etc. in a computer in the international application published as International Publication No. WO00/72228 (hereinafter the proposed colors and system utilizing the same referred to as the “already proposed colors” or “already proposed color system”). By considering applications of a recording method using the already proposed colors, the above recording of information becomes possible.
An object of the present invention is to solve the above problems and provide an identification tag designed to enable recording and display at any time of a detailed manufacturing history or other content of a large amount of information in accordance with necessity by utilizing the limited space at a product, part, printed circuit board, or other object and to enable traceability relating to the manufacturing history etc. of a product etc. and an identified object to which this identification tag is attached.